<li><span class="folder">Books</span>
 <ul>
   <li><span class="folder">Electronic</span></li>
   <li><span class="folder">Hand Printed</span></li>
   <li><span class="folder">Manuscript</span></li>
   <li><span class="folder">Printed</span></li>
 </ul>
</li>
<li><span class="folder">Creators</span>
 <ul>
  <li><span class="folder">Person</span></li>
  <li><span class="folder">Organizations</span></li>
  <li><span class="folder">Events</span></li>
 </ul>
</li>
<li><span class="folder">Dates</span>
 <ul>
  <li><span class="folder">Current</span></li>
  <li><span class="folder">Past 5 years</span></li>
  <li><span class="folder">Past 10 years</span></li>
  <li><span class="folder">Past 20+ years</span></li>
 </ul>
</li>
<li><span class="folder">Films</span>
<ul>
 <li><span class="folder">Formats</span>
 <ul>
   <li><span class="folder">Blu-Ray</span></li>
   <li><span class="folder">DVD</span></li>
   <li><span class="folder">Electronic</span></li>
   <li><span class="folder">HD-DVD</span></li>
   <li><span class="folder">Streaming</span></li>
   <li><span class="folder">VHS</span></li>
 </ul>
 </li>
 <li><span class="folder">Titles</span></li>
</ul>
</li>
<li><span class="folder">Geographic Location</span>
 <ul>
  <li><span class="folder">Continents</span>
    <ul>
	 <li><span class="folder">Africa</span></li>
	 <li><span class="folder">Antarctica</span></li>
	 <li><span class="folder">Asia</span></li>
	 <li><span class="folder">Australia</span></li>
	 <li><span class="folder">Europa</span></li>
	 <li><span class="folder">North America</span></li>
	 <li><span class="folder">South America</span></li>
	</ul>
  </li>
  <li><span class="folder">Space</span>
   <ul>
     <li><span class="folder">Planets</span></li>
	 <li><span class="folder">Sun</span></li>
	 <li><span class="folder">Other</span></li>
   </ul>
  </li>
 </ul>
</li>
<li><span class="folder">Maps</span></li>
<li><span class="folder">Music</span>
<ul>
  <li><span class="folder">Albums</span>
   <ul>
     <li><span class="folder">LP</span></li>
	 <li><span class="folder">Compact Disc</span></li>
	 <li><span class="folder">iTunes</span></li>
	 <li><span class="folder">MP3</span></li>
   </ul>
  </li>
  <li><span class="folder">Scores</span></li>
  <li><span class="folder">Songs</span>
  <ul>
    <li><span class="folder">Artists</span></li>
	<li><span class="folder">Genre</span></li>
    <li><span class="folder">Titles</span></li>
  </ul>
  </li>
</ul>
</li>
<li><span class="folder">Periodicals</span>
<ul>
 <li><span class="folder">Print</span></li>
 <li><span class="folder">Online</span></li>
 <li><span class="folder">Titles</span></li>
</ul>
</li>
<li><span class="folder">Software</span>
<ul>
 <li><span class="folder">Microsoft Windows</span></li>
 <li><span class="folder">Apple Macintosh</span></li>
 <li><span class="folder">Linux/Unix</span></li>
 <li><span class="folder">Game Consoles</span>
 <ul>
   <li><span class="folder">Nintendo Wii</span></li>
   <li><span class="folder">Sony Playstation</span></li>
   <li><span class="folder">Microsoft XBox</span></li>
 </ul>
 </li>
</ul>
</li>
<li><span class="folder">Topics</span></li>
<li><span class="folder">Web Resources</span>
<ul>
 <li><span class="folder">No-cost</span></li>
 <li><span class="folder">Purchased</span></li>
</ul>
</li>